McNamara was a member of the U.S. Marshals Service before he was forced into retirement at 57 due to federal age restrictions. McNamara discovered he wasn't ready to leave law enforcement, so in 2012, he ran for McLennan County Sheriff and won.

Now, the sheriff's story could win a coveted Oscar for his screenplay-writing cousin, Taylor Sheridan.

Sheridan wrote the screenplay for "Hell or High Water" after growing up in Bosque County and idolizing McNamara. It's his second movie penned, with the first being the Writer's Guild of America-nominated "Sicario."

Sheridan consulted the sheriff as he developed the script and worked hand in hand with lead actor Jeff Bridges. McNamara told NBC 5 he also worked very closely with Bridges as he prepared for the role.

McNamara says Bridges looked for advice on everything from clothes to line reading as the mentor/mentee relationship grew. When the crew was ready to film, Bridges nailed down McNamara's Texas look, making them look like twins.

Now, McNamara is in need of advice as he makes plans to head to L.A. on Sunday to walk the red carpet. His trademark Texas threads won't work among the glitzy and glamorous.